Connection and disconnection of hydraulic equipment in hyperbaric environments

Patent metadata

Field	Value
Publication number	US-10107078-B2
Application number	US-201415035948-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 12, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A hydraulically-powered subsea tool system has a tool (26) and a tool power unit (12). The tool (26) communicates with a first connector element (30) on a hydraulic drive circuit (82). The tool power unit (12) has a hydraulic supply circuit (88) communicating with a second connector element (20). The connector elements are wet-mated with each other to connect the circuits for powering the tool. The circuits are pressure-compensated by respective compensators (136,90). When the circuits are connected, a valve (140) is operable to transfer pressure compensation of one of the circuits from the compensator (136) of that circuit to the compensator (90) of the other circuit. The valve (140) suitably transfers pressure compensation of the drive circuit from a drive circuit compensator to a supply circuit compensator.

First claim

The invention claimed is:

1. A hydraulically-powered tool system for subsea interventions, the system comprising:
a tool communicating with a first connector element, the tool and the first connector element being on a hydraulic drive circuit; and
a tool power unit having a hydraulic supply circuit communicating with a second connector element, the first and second connector elements being arranged to be wet-mated with each other to establish fluid communication between the supply circuit and the drive circuit for powering movement of one or more elements of the tool when in use;
wherein:
the drive circuit is pressure-compensated by a drive circuit compensator, minimizing a pressure difference between the drive circuit and a hydrostatic pressure of surrounding environment;
the supply circuit is pressure-compensated by a supply circuit compensator, minimizing a pressure difference between the supply circuit and a hydrostatic pressure of surrounding seawater; and
the system further comprises at least one valve that, when the drive circuit and the supply circuit are in fluid communication, is operable to transfer pressure compensation of one of said circuits from the compensator of that circuit to the compensator of the other circuit.

2. The system of claim 1 , wherein the or each valve is operable to transfer pressure compensation of the drive circuit from the drive circuit compensator to the supply circuit compensator.

3. The system of claim 2 , wherein the or each valve is operable to isolate the drive circuit compensator from the drive circuit.

4. The system of claim 3 , wherein the or each valve is disposed between the drive circuit compensator and the drive circuit so as, when open, to connect the drive circuit compensator to the drive circuit and, when closed, to isolate the drive circuit compensator from the drive circuit.

5. The system of claim 2 , wherein the or each valve is operable to transfer pressure compensation of the drive circuit to the supply circuit compensator in response to increasing pressure in the supply circuit.

6. The system of claim 5 , wherein the or each valve comprises a movable valve element disposed between the supply circuit and a valve seat, to be forced by overpressure in the supply circuit against the valve seat to close the or each valve.

7. The system of claim 2 , wherein the or each valve is integral with the first connector element.

8. The system of claim 2 , further comprising a pressure-relief valve communicating with the drive circuit compensator, wherein the or each valve that is operable to transfer pressure compensation is disposed between the pressure-relief valve and the supply circuit.

9. The system of claim 1 and comprising a flexible hose coupling the tool to the first connector element.

10. The system of claim 1 , wherein the first connector element is integrated with or rigidly attached to the tool.

11. The system of claim 1 , further comprising a locking system that is powered for locking the first and second connector elements in fluid communication and that is biased to unlock the first and second connector elements on loss of power.

12. The system of claim 1 , further comprising an ejection system that is powered to allow the first and second connector elements to be brought into fluid communication and that is biased to force apart the first and second connector elements on loss of power.

13. The system of claim 1 , wherein the tool power unit is positioned in an underwater vehicle or in a power module attached to an underwater vehicle.

14. The system of claim 13 , wherein the tool is arranged to be supported by the underwater vehicle in which the tool power unit is positioned or to which the power module is attached.

15. A method of pressure compensation when using a hydraulically-powered tool system for subsea interventions, the method comprising:
wet-mating connector elements to establish fluid communication between a pressure-compensated hydraulic supply circuit and a pressure-compensated hydraulic drive circuit of a tool; and
transferring pressure compensation of a first of said supply and drive circuits to a compensator acting on a second of said supply and drive circuits, minimizing a pressure difference between the supply and drive circuits and a hydrostatic pressure of surrounding seawater.

16. The method of claim 15 , comprising isolating the first circuit from a compensator acting on the first circuit.

17. The method of claim 15 , comprising transferring pressure compensation of the drive circuit to a compensator acting on the supply circuit.

18. The method of claim 17 , comprising transferring pressure compensation of the drive circuit in response to increasing pressure in the supply circuit.

19. The method of claim 18 , comprising wet-mating the connector elements before increasing pressure in the supply circuit to a tool drive pressure.

20. A connector element for a hydraulically-powered subsea tool system, wherein:
the element communicates with a hydraulic drive or supply circuit that is pressure-compensated by a compensator, minimizing a pressure difference between the circuit and a hydrostatic pressure of surrounding seawater; and
the element comprises at least one first valve for opening and closing a fluid flow path through at least one port between the connector element and a hydraulically-powered subsea tool, and at least one second valve that is operable to transfer pressure compensation of the circuit from that compensator to a compensator of another circuit to which the connector is wet-mated in use.

21. A combination of connector elements for a hydraulically-powered subsea tool system, at least one of those elements being as defined in claim 20 , wherein:
a first connector element is on a hydraulic drive circuit;
a second connector element is on a hydraulic supply circuit for supplying hydraulic fluid to the drive circuit when the connector elements are wet-mated in use;
the drive circuit is pressure-compensated by a drive circuit compensator;
the supply circuit is pressure-compensated by a supply circuit compensator; and
one or more of the at least one second valve is operable to transfer pressure compensation of one of said circuits from the compensator of that circuit to the compensator of the other circuit.

Assignees

• Subsea 7 Ltd

Inventors

• Taylor Robert Ian
• Gibbons Graham

Classifications

• E21B41/0007 Primary

  for underwater installations (E21B41/005, E21B41/04, E21B41/06, E21B41/08, E21B41/10 take precedence) · CPC title

• E21B41/04

  Manipulators for underwater operations, e.g. temporarily connected to well heads · CPC title

• B63C11/52 Primary

  Tools specially adapted for working underwater, not otherwise provided for · CPC title

• B63G8/001

  Underwater vessels adapted for special purposes, e.g. unmanned underwater vessels; Equipment specially adapted therefor, e.g. docking stations (self-propelled or direction controlled diving chambers with mechanical link to a base B63C11/42) · CPC title